The present invention relates to a system and a method for obtaining, for the purpose of analysis, real-time engine knock data derived from an operating, subject internal combustion engine. In particular, it relates to such a method and an associated system which advances the state of the art respecting capturing and assessing engine knock data in a manner which is both capable of acquiring and analyzing such data very rapidly, and which decidedly offers advanced precision identification and characterization of internal combustion engine knock.
Engine knock is a behavior wherein the normally controlled burn activity of an internal combustion engine is perturbed by premature ignition of the fuel/air mixture. There are many causes of knock, and it is very important to eliminate the possibility of excessive knock of any type so as to prevent serious damage to an engine, and loss of significant engine power and operating efficiency.
Despite advances heretofore in the science of addressing the issue of engine knock issue, the “gold standard” for real-time knock detection involves the bolting of a copper tube to the block of an engine for the purpose of permitting a trained technician to listen, via the tube, for audible sounds believed to be interpretable as knock. This very subjective and error-prone method is, of course, often quite unacceptable, and accordingly, there have been many efforts in recent years directed toward developing more sophisticated techniques for assessing internal combustion engine knock.
The present invention, recognizing that there have been many “science side” (rather then “art side”) proposals and advancements for detecting and analyzing engine knock, nonetheless offers a significant and unique advance in the ability to accomplish precision, analyzable knock detection, and to do so very rapidly, very accurately, and on-the-fly, so-to-speak, during real-time engine operation. In a manner of thinking about the practice proposed by the present invention, that practice is based upon having access, effectively, to a body of engine-noise-reduced, frequency-domain-spectral, engine-operating, energy-content data derived from an operating engine—data of a kind which is expected to contain, in one or more selected, knock-related frequency bands (referred to herein as spectral bins), evidence of any engine-knock behavior. Such access leads, in accordance with practice of the invention, toward the step of comparing the sum total of noise-reduced spectral energy reflected in those selected spectral bins with a pre-determined spectral energy threshold value, with a positive declaration of the presence of engine knock behavior being made upon a determination that this spectral bin-sum total exceeds the mentioned threshold value.
Implementation of the methodology of the invention, as will be understood from the description which follows below, is practiced on a cycle-by-cycle basis over one, or any suitable plurality of engine operating cycles, with relevant data—typically cylinder-pressure data, being collected in real time, initially in the time domain, over an intentionally windowed range of engine crank angles.
Another way of expressing the unique practice of the present invention is to describe it as one involving determining, along the route of declaring there to be, or not to be, a positive indication of engine knock behavior, whether the sum-total energy-content value represented in at least one selected, knock-relevant spectral bin of the type just mentioned above, appropriately noise reduced, exceeds the value of the above-mentioned, predetermined spectral energy threshold.
These and other important features and advantages which are offered by the present invention will become more fully apparent as the below-following description of the invention which follows below is read in conjunction with the accompanying several drawings.